This article shows a climate change mitigation strategy by means of membranes replacement and determination methodology of carbon footprint in reverse osmosis (RO) desalination plants, valid for all the islands, and even isolated territories in the continent. This study takes the case of study of Canary Islands, where there are more than 320 desalination plants with different sizes, private, and public. The objective is to propose a new method which integrates this analysis with the replacement of membranes, from 0% to 20% per year in sea water reverse osmosis desalination plants, to reduce the carbon footprint and ecological footprint. If it is considered a replacement of 20% of the elements per year, the carbon footprint could be reduced to between 5% and 6% and even more if it is introduced low energy consumption membranes instead of high rejection elements. The factor mix in Canary Islands, according to the technological structure of the generation park that uses oil products, is around 0.678 kgCO₂/kWh, much higher than in the Spanish mainland where it is 0.263 kgCO₂/kWh. Therefore, it is estimated in Canary Islands 5,326,963 t CO₂/year can be emitted, which represents 2.4 tCO₂/person/year, 12 times more the admissible admissions per inhabitant in the Canary Islands, only considering the seawater desalination sector. This document shows the different results of the analysis of energy efficiency and the environmental footprints. This study may serve as a tool for the decision-making processes related to how to improve energy efficiency in desalination plants.

This paper reports results of a 5-year trial study of a natural treatment system for wastewater (NTSW) on a livestock pig farm on Gran Canaria (Canary Islands, Spain). The pilot plant consist of a rotary screen, a first-generation multi-chamber digester, and two horizontal subsurface flow treatment wetlands (HSFCW) with a pond installed between them. Results show that the removal efficiency of total chemical oxygen demand (CODt), total suspended solids (TSS), volatile solids (VS) and total dissolved solids (TDS) of the treatment were 91.77%, 95.99%, 82.62%, and 55.78%, respectively. Other removal values include 93.79% for total nitrogen (TN) and 93.05% for phosphorus (P₂O₅). The results demonstrate the suitability of NTSW solutions applied to livestock waste in pig farms and their potential application to other farms of similar size.

In this study, the main elements that can make up a Natural Treatment System for Wastewater (NTSW), its most important parameters and properties of operation and design, have been analyzed, as well as the environmental problems derived from the generation of large amounts of slurry. The objective of this paper is to propose a methodology to improve the operation of these systems, associated with small and medium-sized livestock farms, in insular and isolated systems such as the Canary Islands. An Integrated and Resilient System (IRS) for monitoring and measuring operational variables quasi-continuous and in situ is proposed. Low-cost technology and open source hardware are employed, as well as application of the IoT (Internet of Things) strategies to share and analyze the information collected in the cloud. In view of the high degree of resilience and the simplicity of this type of technology, as well as its low cost, it is concluded that it is feasible to create a measurement system with these characteristics that can be used for NTSW parameterization, and other purposes. Satisfactory results were obtained for several parameters (ambient temperature, relative humidity, UV radiation, atmospheric pressure). It is presented as a novel proposal based mainly on low-cost technology and free software with which to improve the NTSW operation process.